The present invention relates to poly(arylether)/liquid crystalline polyester block copolymers and to a process for their production.
Liquid crystalline polyesters form anisotropic melts and solutions which can be processed to form ultra high strength and ultra high modulus fibers, films, and molded articles. See, e.g., Advances in Polymer Science, Vol. 59, Springer-Verlag, Heidelberg (1984) and ACS Symposium Series 435, Weiss et al editors, American Chemical Society (1990). These materials could therefore be useful as reinforcing materials in polymer composites.
It is, however, difficult to prepare composite polymer materials with liquid crystalline polyesters because the liquid crystalline molecules aggregate and do not mix with the random coil matrix material. Block copolymers of liquid crystalline polymers have been prepared by coupling two telechelic oligomers or by polymerizing monomers in the presence of telechelic oligomers. See, e.g., Waehumad et al, Polymer Preprint 1989, pages 252-253 and McGrath et al Poly. Eng. Sci. Volume 17, page 648 (1977). It has been found, however, that such processes are not very effective because phase separation occurs and only a small amount of block copolymer forms. See, e.g., Auman et al, Polymer, Volume 29, page 938 (1988).